1. Technical Field
This device relates to telescopic gauges that are used to transfer the interdimensions of a cylinder for measuring purposes within thousandths of an inch.
2. Description of Prior Art
Prior art devices of this type have relied on a variety of different structural configurations that are adapted to provide automatic centering of measuring gauges within cylinders. Examples of such are U.S. Pat. Nos. 2,470,635, 3,836,277, 4,754,551 and 4,773,164.
Commercial examples of self-centering gauges are shown in cylinder gauges nos. 452B and 84 in Starrett.RTM.--catalog and bore gauge series 511-526 by Mitutoyo catalog, page 285.
Telescopic gauges of this type to which the invention is designed to adapt to are shown in Starrett.RTM. catalog, page 131 (telescopic gauge no. 829 and 579 series). The telescoping gauges no. 579 series are used to transfer internal measurements from the cylinder to be measured with precision calibers. These gauges have opposite telescopically extensible spring-urged contact plungers that can be locked once within the cylinder and then removed and measured.
In one form of applicant's invention, the centering tool is adapted to be fitted over and adapted to one of the plunger supports providing a pair of angularly offset guide pins to center the gauge within the cylinder without multiple efforts.
In cylinder bore gauges no. 164 of Mitutoyo reference 511-164 and 84 of Starrett page 364 series self-contained measuring gauges and cylinder engagement surfaces are shown wherein the gauges measure directly the distance between the contact points that extend outwardly from the gauge head. Bore gauge 84 series has a fixed pin opposite a measuring plunger with two positioning pins in offset angular relation thereto.
In U.S. Pat. No. 2,470,635 a gauge is positioned on a central shaft. The gauge has a pair of chucks with resilient jaws extending therefrom.
In U.S. Pat. No. 3,836,277 a centering tool is disclosed wherein a tool is centered within a cylinder by multiple pins on the respective spring-urged arms pivoted about and to the tool.
U.S. Pat. No. 4,754,551 is directed to a centering gauge tool in which multiple sensing fingers are mounted on a conical insert and expand outwardly to engage the inner surface, centering and measuring the tool.
In U.S. Pat. No. 4,773,164 a self-aligning caliber bar is disclosed in which two sets of aligned spaced pivoting fingers extend outwardly from a central mounting body to align same within a cylinder enclosure.